1. Field of the Invention
The present invention relates to a recording method, a recording apparatus and a recording medium, capable of recording information to a rewritable optical disk such as DVD-RW (DVD-rewritable).
This application claims the priority of the Japanese Patent Application No. 2002-134747 filed on May 9, 2002, the entirety of which is incorporated by reference herein.
2. Description of the Related Art
Conventionally, there are available DVDs as large-capacity optical disks including writable DVDs (digital versatile disk) such as a DVD-R (DVD-recordable), DVD-RW (DVD-rewritable) and DVD-RAM (DVD-random access memory). Of these DVDs, DVD-R and DVD-RW having video data recorded therein in a format complying with the DVD video format can be played by a reproduce-only optical disk player. Further, an optical disk having data recorded in the universal disk format (UDF) can be reproduced by a computer to reproduce the data.
FIG. 1 shows a chart explaining the DVD video format-based logical format of an optical disk. As shown in FIG. 1(A), the optical disk having this logical format has the information recording area thereof divided into a zone called “lead-in” at the innermost circumference thereof, a data zone and a zone called “lead-out” at the outermost circumference. The optical disk will have desired video data or the like recorded to the data zone thereof.
As shown, the data zone consists of a UDF (universal disk format) area (file system area) A1 in which a UDF bridge configuration is stated, VMG (video manager) area (DVD management information area) A2 and a real-time data recording area A3 in this order from the lead-in zone. The UDF and VMG areas are provided to record management information used to manage files of video data recorded in this optical disk. Of these UDF and VMG areas, the VMG area A2 being a second management information recording area is directed to a file management system unique to the DVD video format and will have recorded thereto TOC information (table of contents) used for management of all video data recorded in the real-time data recording area A3. On the other hand, the UDF area A1 being a first management information recording area is directed to a file management by a computer, and will have recorded thereto management information used for management of all the video data recorded in the real-time data recording area A3 in a format compatible with the file management system of the computer.
As shown in FIG. 1(B), the real-time data recording area A3 is a program area where real data are to be recorded, and will have video data recorded therein in units of VTS (video title set; will be referred to simply as “title” wherever appropriate hereunder). It should be noted that a maximum of 99 VTSs can be provided. It is also important to note that as shown in FIG. 1(C), the “VTS” is composed of VTSI (video title set information), VTSM VOBS (video object set for the VTSM), VTSTT VOBS (video object set for titles in a VTS), and VTSI BUP (backup of VTSI) in this order. VTSTT VOBS will have recorded thereto MPEG (Moving Pictures Experts Group)-2-formatted video data as real video data, VTSI will have recorded thereto the address information etc. for management of the video data composed of real data, and VTSTT VOBS will have a title menu of the video data recorded thereto. It should be noted that VTSTT VOBS is an option and VTSI BUP is a backup of VTSI.
When the above optical disk is accessed by a computer, a desired file can be searched based on UDF for reproduction. When the optical disk is reproduced by a DVD player, a desired file can be searched based on VMG for reproduction.
Video data is written to such an optical disk by either an incremental recording method (will be referred to as “INC method” hereunder) or restricted overwrite method (will be referred to as “ROW method” hereunder). The INC method is intended for sequential recording of video data, while the ROW method is applied to an overwritable optical disk. In the ROW method as well, however, video data which are to be recorded to a fresh (unrecorded) area will sequentially be recorded. In these INC and ROW methods, an RMA (recording management area) formed along the inner circumference of the lead-in zone provides an area management such as a recording programming of the optical disk.
FIG. 2 is a chart for explaining the INC-based recording procedure. For the INC-based recording, it is defined that data should be recorded to up to three areas each called “Rzone”. Each Rzone is managed under the RAM standard.
More specifically, in the INC-based recording of moving pictures, Rzones are first reserved as shown in FIG. 2(A). For this reservation of Rzones, a Rzone 1 for UDF and VMG areas in which management information is to be recorded is defined, a next Rzone 2 for VTSI and VTSM VOBS of a top VTS is defined in an unrecorded area forming a real-time data recording area, and a remaining unrecorded area is defined as “invisible Rzone”. In the INC method, the management information recording area and also the areas in which VTSI and VTSM VOBS of the top VTS are formed are reserved by reserving the Rzone1 and Rzone2.
In the INC method, VTSTT VOBS of real data is defined by recording video data sequentially starting at the beginning of “Invisible Rzone”. Further, upon completion of recording of the real data under one title with a user's instruction, VTSI BUP is recorded next to the recording of the real data as shown in FIG. 2(B) and VTSI and VTSM VOBS are defied in the Rzone 2 again at the beginning and the Rzone 2 is closed as shown in FIG. 2(C). Thus, one VTS is recorded to the optical disk by the INC method.
In the INC method, for continuously recording a next title, Rzone 3 is reserved in a remaining unrecorded area and areas are reserved for VTSI and VTSM VOBS to define the “Invisible Rzone” as shown in FIG. 2(D). Further, after defining VTSTT VOBS by recording real data, VTSI BUP is defined as shown in FIG. 2(E), and VTSI and VTSM VOBS are reserved in the previously reserved areas as shown in FIG. 2(F). Thus, a next VTS is recorded as shown in FIG. 12(G). In the INC method, when a title is recorded next, unrecorded areas are defined similarly to sequentially record VTSs to the areas.
On the other hand, in an optical disk having VTSs sequentially recorded therein to define a real-time data recording area, there are defined areas for UDF and VMG by finalization by the INC method to define lead-in and lead-out zones as shown in FIG. 2(H). Thus, the optical disk is interchangeable with a read-only optical disk. It should be noted that in defining the UDF and VMG areas, UDF and VMG data are generated based on the data in the areas for the tiles VTSI and VTSM VOBS, and the data are recorded to the Rzone 1 which will thus be closed.
FIG. 3 shows a chart for explaining the ROW-based recording procedure. In the ROW method, a lead-in, UDF and VMG areas, and areas for recording the leading titles VTSI and VTSM VOBS are pre-reserved by padding as shown in FIG. 3(A). It should be noted that the “padding” refers to a process for reserving an area by recording there dummy data such as null (zero) or the like.
In the ROW method, when these areas are reserved, video data are sequentially recorded to define a VTSTT VOBS composed of real data as shown in FIG. 3(B). Upon completion of recording the real data under one title, a VTSI BUP area is defined, and padding is done for reserving recording areas for subsequent titles VTSI and VTSM VOBS, as shown in FIG. 3(B). Then, reservation of VTSI and VTSM VOBS areas for recording the real data will be repeated again from the beginning as shown in FIG. 3(C). Thus, one VTS is recorded in the optical disk by the ROW method.
In the ROW method, for continuously recording a next title, real data are recorded following a padded area composed of a preceding VTS to define VTSTT VOBS and VTSI BUP areas, and then padding is done for reserving subsequent titles VTSI and VTSM VOBS, as will be known from FIG. 3(D). Subsequently, areas are defined for titles VTSI and VTSM VOBS as shown in FIG. 3(E) to thereby record successive VTSs to the optical disk as shown in FIG. 3(F). In the ROW method, for successively recording titles, similar padding is done to record VTSs sequentially.
On the other hand, in an optical disk having such VTSs sequentially recorded therein to define a real-time data recording area, the ROW method defines UDF and VMG areas by finalization as in the INC method, and then lead-in and lead-out as shown in FIG. 3(G) to thereby establish interchangeability with a read-only optical disk. It should be noted that the UDF and VMG areas are defined by producing UDF and VMG data from the VTSI and VTSM VOBS title data and recording the data to an inner-circumferential leading area by padding.
Note that generally speaking, when recording data in the DVD video format to a DVD-RW medium, a file system is required which manages the intermediate state. In case data is recorded only in the DVD video format, information with which VTSs are managed is held in the intermediate-state management file system as well. Thus, when a VTS is deleted, it is detected which one of LSNs (logical sector number) in the medium becomes correspondingly blank, which information is used to record a new VTS to such a temporary space.
The Japanese laid-open patent No. 2002-063765 discloses a technique for making real-time recording of information to a DVD-R in such a manner that the information can also be reproduced by a read-only DVD player having information recorded therein regardless of any real time. With this disclosed video technique, when information is recorded to the DVD-R in compliance with the DVD video standard defined including at least VTS including VOBS to be produced and its corresponding VTSI and VMGI intended for control of one VTS or more, the VTS is recorded to the DVD-R, then provisional VMGI is generated which is provisional control information corresponding to the recorded VTS and used to define VMGI later for recording to the DVD-R, and the provisional VMGI thus generated is recorded to the DVD-R each time a VTS is recorded to the DVD-R. As above, when information to be recorded in units is recorded, the provisional control information is generated and recorded temporarily in a rewritable recording medium. Thereby, even when a plurality of pieces of information to be recorded in units has been recorded in the rewritable recording medium, by accurately recording real management control information later with the use of provisional control information including latest contents, it is possible to make real-time recording of information to the rewritable recording medium in compliance with a read-only recording medium-oriented recording format not based on any real-time information recording.
However, it is desired to record also extension files such as JPEG files other than DVD video files to a DVD-RW medium.
For example, it is conceivable that such an optical disk is played in place of the magnetic tape in a portable video camcorder. In this case, since some conventional video camcorders can record moving pictures as well as still pictures, such an optical disk for use with the portable video camcorder should also desirably be capable of recording still pictures other than moving pictures.
Even when such an extension file is held in the intermediate file system, management information is necessary to know the space availability.
Also, in case no extension file is supported, it cannot be known at which LSN recording should be started.